A-44 Free Communication/Poster - Cardiovascular Responses to Exercise Wednesday, May 31, 2017, 7: 30 AM - 12: 30 PM Room: Hall F
Cognitive Task Impairs Dynamic Cerebral Autoregulation During Normoxia And Hypoxia.
295 Board #116 May 31 11
00 AM - 12
Hypercapnia-induced cerebral hyper-perfusion or hypoxia attenuates dynamic cerebral autoregulation (CA). On the other hand, performing cognitive task increases both anterior and posterior cerebral blood flow via frontal and occipital lobe activation and this cognitive tasks-induced cerebral hyper-perfusion attenuates dynamic CA.
PURPOSE: The aim of the present study was to examine whether cognitive task-induced impairment in dynamic CA was enhanced by hypoxia condition.
METHODS: To test our hypothesis, we identified dynamic CA during the Go/No-Go task under normoxia and hypoxia conditions. This study examined the relationship between mean arterial pressure (MAP) and mean middle cerebral artery blood velocity (MCA Vmean) during the Go/No-Go task. Dynamic CA and steady-state changes in MCA V in relation to changes in arterial pressure were evaluated using transfer function analysis.
RESULTS: MCA Vmean increased with the Go/No-Go task (P=0.022), but the different response of MCA Vmean between normoxia and hypoxia conditions was not observed (P=0.850). In the transfer function analysis, the low frequency (LF) and very LF (VLF) phase shift decreased during the Go/No-Go task (LF and VLF; P <0.001 and P=0.01). However, the decreases in LF and VLF phase shift during the Go/No-Go task was not modified by hypoxia condition (P=0.617 and P=0.981).
CONCLUSIONS: Similarly with change in MCA Vmean, dynamic CA was attenuated during cognitive task. In contrast to our hypothesis, hypoxia did not affect this phenomenon.© 2017 American College of Sports Medicine